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Oracle GoldenGate Initial Loading: Oracle Database to Oracle Database

For Oracle DB to Oracle DB initial loading, you can use the following approaches:

Import/Export with the flashback_scn option and start replication with aftercsn

Backup with RMAN and start replciat with atcsn

Different Between SCN and CSN
SCN is used in Oracle Database means SCN (System Change/Commit Number). CSN is used by Oracle GoldenGate means CSN (Checkpoint Sequence Number). They both refer to the same number for Oracle database transactions.

â€‹1. Import/Export with flashback and start replication with AFTERCSN.
The steps are as follows:â€‹

When to use ATCSN and AFTERCSN?ATCSN means start applying from that SCN. So transaction with that particular SCN is included. ATCSN is used to start replicat if RMAN is used to instantiate target. From Database Backup and Recovery Reference, UNTIL SCN specifies an SCN as an upper limit. RMAN restore or recover up to but not including the specified SCN.

AFTERCSN is used to start replicat if datapump is used to instantiate target. The export operation performed is consistent as of FLASHBACK_SCN. AFTERCSN means starting from “that SCN+1”. Transaction with that SCN isn’t included. â€‹